Scalars And Vectors

Every Quantity in the world of Physics can be classified as either a scalar or vector.
When looking at a formula, think about this.

For example, if you push a body of mass m on a frictionless floor, it will accelerate according to Newton`s Second Law:
Force = Mass x Acceleration

Here we have:

Vector = Scalar x Vector.

This means that the Force exerted is in the same direction as the acceleration produced.
For Example..if you would like to accelerate a 10kg mass by an acceleration 3i + 4j+ 5k you will need to apply a force of 10(3i +4j + 5k) = 30i + 40j +50k

Two vectors can be added or subtracted by scaled diagrams, geometry, trigonometry, or pythagoras depending on the orientation, but the multiplication of two vectors is much more complex and there are two pleasing possibilities:

Scalar Product ....which produces a scalar (example Force x Displacement = Work)

Vector Product.... that produces a vector in a new mutually perpendicular dimension (example: the force on on moving charge travelling through a magnetic field, makes the particle bend in a direction perpendicular to the travel direction and the magnetic field direction.

Summary
When two vectors are multiplied together , the angle between those vectors DOES matter.
Physics A Level Formula sheets usually assume the angle between the vectors being multiplied are either

(0 in the case of scalar product)

or

(90 in the case of Vector product)